VXDElectronDeposit.h

/**************************************************************************
 * BASF2 (Belle Analysis Framework 2)                                     *
 * Copyright(C) 2014 - Belle II Collaboration                             *
 *                                                                        *
 * Author: The Belle II Collaboration                                     *
 * Contributors: Martin Ritter                                            *
 *                                                                        *
 * This software is provided "as is" without any warranty.                *
 **************************************************************************/
 
#pragma once
#ifndef VXD_SIMULATION_ELECTRONDEPOSIT_H
#define VXD_SIMULATION_ELECTRONDEPOSIT_H
 
#include <algorithm>
#include <cmath>
 
namespace Belle2 {
  class VXDElectronDeposit {
  public:
    enum EBits {
      c_FractionBits = 10,
      c_ElectronBits = 22,
      c_TotalBits = c_FractionBits + c_ElectronBits,
      c_MaxFraction = (1 << c_FractionBits) - 1,
      c_MaxElectrons = (1 << c_ElectronBits) - 1,
    };
 
    explicit VXDElectronDeposit(unsigned int packed): m_packed(packed) {}
 
    VXDElectronDeposit(float fraction, float electrons)
    {
      const unsigned int intfrac = std::round(std::max(0.f, fraction) * c_MaxFraction);
      const unsigned int intelec = std::round(std::max(0.f, electrons));
      m_packed = std::min(intfrac, (unsigned int) c_MaxFraction)
                 + (std::min(intelec, (unsigned int) c_MaxElectrons) << c_FractionBits);
    }
    float getFraction() const
    {
      return (m_packed & c_MaxFraction) * 1.0 / c_MaxFraction;
    }
    unsigned int getElectrons() const
    {
      return (m_packed >> c_FractionBits) & c_MaxElectrons;
    }
    unsigned int getPacked() const { return m_packed; }
    operator unsigned int() const { return m_packed; }
  private:
  unsigned int m_packed: c_TotalBits;
  };
 
} //Belle2 namespace
#endif // VXD_SIMULATION_ELECTRONDEPOSIT_H